HEK293T cells were transfected with the pCMV6-ENTRY control (Cat# PS100001, Left lane) or pCMV6-ENTRY MAPK1 (Cat# RC204703, Right lane) cDNA for 48 hrs and lysed. Equivalent amounts of cell lysates (5 ug per lane) were separated by SDS-PAGE and immunoblotted with anti-MAPK1 (Cat# TA500468). Positive lysates [LY408481] (100 ug) and [LC408481] (20 ug) can be purchased separately from OriGene.